1. Field of the Invention
This application is directed to a position sensitive illumination system.
2. Description of Related Art
Typical patients with sleeping disorders, such as obstructive sleep apnea (OSA), and even people (also referred to herein as “patients”) without sleep breathing or other disorders can remain in an awake state lying in bed prior to going to sleep. Some patients may prefer to read a book or relax before going to sleep.
The bedroom environment at night and during sleep is typically poorly lit or not illuminated at all. The patient may therefore use a room light or switch on a bedside lamp to read. Bedside lamps typically throw stray light in most directions and may disturb a sleeping bed partner.
Another problem is that occasionally patients at night find need to get up and visit the bathroom or kitchen, or the need to otherwise arise. Typically, such a patient will switch on a light by fumbling in the dark for a light switch or search for a nearby flashlight.
A patient's travel or walking path during such visits should preferably be lit, therefore either room lighting or a flashlight is required, the latter to prevent disturbing a bed partner.
Some patients may also use a light-activated lamp or “night light” that plugs into a general purpose power outlet in the home. The lamp illuminates a space in the adjacent vicinity when ambient light levels fall. The space remains illuminated whether the patient or bed partner is awake or asleep. This stray light can disturb patients and bed partners when they wish to sleep. They also illuminate only a defined space, rather than the intended path of movement for a patient, e.g., the path from the bed to the bathroom.
Further, switching on of room lights can have a negative effect on circadian rhythms. Strong illumination especially reflected into the eyes is known to wake up patients, e.g., to a level of alertness that may diminish their ability to fall asleep again.
Therefore, a need has arisen to develop a system to allow for convenient and automated lighting of a patient's intended path, while preferably providing minimal disturbance to a patient and the patient's bed partner.